radioactive material from its protective case. health officials say six men, aged between 16 and 38, visited the hospital between late thursday and early friday under police guard. they were tested for signs of radiation exposure. the officials say one of them was treated after complaining of a headache and nausea. police say they detained the six men, based on the truck driver's statement. the authorities plan to investigate the case further, after the men have finished undergoing medical tests. an event featuring south korean food has been held in tokyo. the country's traditional food culture, known as kimmon, was recently designated as an intangible cultural asset, along with japanese cuisine. the south korean embassy organized the event on saturday to deepen cultural exchange between the people of japan and south korea.